With conventional image forming apparatuses (printing apparatuses), buttons having a mechanical mechanism (hereinafter, referred to as “hardware buttons”) are generally used as input operation units. However, in recent years there are known to be apparatuses that have a more graphic liquid crystal display unit and a touch panel (including a tablet apparatus) via which operations and input can be performed using a finger, touch pen, or the like on buttons formed by graphic images created on the liquid crystal display (hereinafter, referred to as “software buttons”).
Japanese Patent Laid-Open No. 2009-211704 proposes an apparatus configured including an operation unit made up of only a touch panel that has almost no hardware buttons. Also, although touch panels have normally been single-touch panels that can accept user input at only one point at a time, in recent years there have also been multi-touch panels that can accept input at multiple points at the same time. When a multi-touch panel is used, it is possible to apply multiple simultaneous input for inputting an intuitive operation such as screen zooming. When buttons on a touch panel are operated, it is desirable to perform control such that unnecessary input is discarded and only one input is accepted at a time in order to improve the user interface, as disclosed in Japanese Patent Laid-Open No. 2009-211704 as well.
However, conventional technology has problems such as the following. Although there has been an increase in the number of apparatuses that realize user input using a touch panel as mentioned above, hardware buttons that are independent of a touch panel have superiority in that they can always be pressed by the user in any situation. Specifically, it is desirable for buttons that are frequently pressed and buttons that have a critical function, such as a switch for urgent stopping, are provided as independent hardware buttons instead of being provided on the touch panel. For example, physical buttons are characteristic in that they can always be pressed, even if the user is performing an ongoing input operation on the touch panel, and even if the touch panel becomes stuck in the pressed state due to some sort of failure, and thus physical buttons can contribute to an improvement in usability.
However, if such hardware buttons can be eliminated, the apparatus can be given a more sleek visual appearance, and cost can be reduced. These hardware buttons can be eliminated by merely displaying physical buttons on the touch panel at a position that can always be pressed. However, since normal touch panels are created such that button input is performed using only one finger, it has not conventionally been possible to provide a physical button's characteristic ability to always be pressed.